Plant growth regulation



Patented June 22, 1954 UNITED STATES PATENT OFFICE PLANT GROWTHREGULATION Nathaniel Tischler, Palmyra, N. .l., assignor to SharplesChemicals Inc., a corporation of Dela- Ware No Drawing. ApplicationAugust 18, 1950, Serial No. 180,320

18 Claims. 1

This invention relates to new and improved compositions of matter whichare used for treating growing plants to alter the normal life cycle ofsaid plants with advantageous results. It is particularly concerned withphytotoxic compositions which contain at least one of the 3,6-endoxohydro-orthophthalic acids as active ingredient, that is, as plantresponse agent.

Phytotoxic compositions containing at least one of the aforesaid acids,and particularly 3,6- endoxo l,2,3,6 tetrahydro orthophthalic acidand/or 3,6-endoxohexahydro-orthophthalic acid, per se or in equivalentform, and more particularly the exo-cis isomers, are highly effectivefor the purpose, and it is a feature of this invention to providecompositions containing the above active ingredients in admixture withsimple, readily available materials which enhance, or intensify theplant response activity of the above active ingredients. These and otherfeatures will become apparent to persons skilled in the art as thespecification proceeds.

Co-pending application Serial No. 81,026, filed March 11,1949, byNathaniel Tischler and Ernest P. Bell, now Patent 2,576,080 grantedNovember 20, 1951, teaches the efficacy of the3,6-endoxohydro-orthophthalic acids and their derivatives in bringingabout useful plant response efiects such as leaf abscission (partial orcomplete),

blossom thinning, vine-kill, total destruction of the plant,adventitious root formation, or delay of fruit drop, the particularplant response manifested depending to a large extent upon the appliedconcentration of the response agent, and the species and degree ofmaturity of the plant undergoing treatment.

The use of 3,6endoxohexahydro-orthophthalic acid, per se or inequivalent form, for the above purposesis particularly described andclaimed in the co-pehding application of Ernest P. Bell and NathanielTischler, Serial No. 131,501, filed December 6, 1949 now Patent2,576,081 granted November 20, 1951; and the use of3,6-endoxol,2,3,6tetrahydro-orthophthalio acid, per se or in equivalentform, for such purposes is particularly described and claimed in theco-pending application of the same inventors, Serial No. 131,502, filedDecember 6, 1949 now Patents 2,576,082 granted November 20, 1951. Bothof these applications are continuations-in-part of said first-mentionedapplication.

The above-mentioned compounds as applied to plants may be in the form ofthe acid per se or in other form, such as in the form of the anhydrideand/or a salt which contains the corresponding anion or anions of orthoconfiguration, the same as in the case of the acid per se, said anion oranions being either acid or neutral in character, in chemicalcombination with a sufficiency of cation or cations to satisfy valencerequirements, such as one or more metal and/or metalloid cations such assodium, potassium, calcium, strontium, magnesium, aluminum, iron,cobalt,.nickel, zinc, cadmium, mercury, copper, ammonium, mono-, diandtrialkylammonium, mono-, diand trialkanolammonium, and mixedalkylalkanolammonium which is N-substituted by from 2 to 3 radicals ofthe type indicated.

Thus the acid is the active material, and this is true whether it isused as such, or in the form of a salt, or anhydride, or other form.These changes at the carboxyl groups are mere changes in form ratherthan changes in substance.

Turning now to the present invention, which for convenience will bedescribed more particularly with reference to3,6-endoxohexahydroorthophthalic acid and3,6-encloxo-l,2,3,6-tetrahydro-orthophthalic acid (per se or inequivalent form) as active plant response ingredients of my newcompositions, it is pointed out that said acids are appreciably solublein water. The other forms are also Water-soluble. Some of them arehighly soluble, while others have a lesser degree of solubility.However, it is preferred to employ compounds having a solubility inwater to the extent of at least 0.1% by weight, and still moreparticularly of at least 1% by weight.

Water solubility is desirable so that anions (acid or neutral or both)are formed when the acids, per se or in chemically equivalent form, aredissolved in water. The desirability of such anions will presentlybecome apparent.

Acid anions may be theoretically illustrated by reference to the acid3,6-endoxohexahydroorthophthalate anion, by which is meant a univalentanion having a structure defined by the formula CH (III) wherein X is acation, usually considered by modern theory to be hydrogen.

Neutral anions may be theoretically illustrated by reference to theneutral 3,6-endoxohexahydroorthophthalate anion, by which is meant adivalent anion having a structure defined by the formula CH O or. 50minsHz CHC-O \i ll Theoretically, similar anions are formed when thetetrahydro acid or its chemically equivalent forms are dissolved inwater.

Although the present applicant does not wish to be bound by anyparticular theory as to the mechanism whereby useful plant responseeffects are produced, a considerable amount of experimentation stronglyindicates that said effects are brought about by the existence inaqueous media of anion or anions (acid and/or neutral) of the typeillustrated above. Both neutral anion and acid anion are effective. Asalient feature of this theory is that the acid or acids of theinvention, when applied per se, or in other form, to a living plant,makes the desired anion or anions (acid and/or neutral) available to theplant, at or near the site of application, and through translocationphenomena, at points far removed from the site of application.

The desired anion or anions are made available by virtue of the factthat the acids per se,

and their other forms, are water-soluble and ionizable. Therefore, whensuch a compound is absorbed into the vascular system of a plant, itdissolves in the aqueous plant juices and provides the functioning anionor anions. The resulting physiological activity is believed to beascribable to the presence of said anion or anions. The acids per se andtheir other forms may thus be regarded as very convenient media forfurnishing the desired anion or anions to susceptible portions of theplant.

It follows, therefore, that the acids per se and their other forms areequally usable.

The foregoing compounds are highly effective for the intended purpose.

have discovered that the amount of the respective compounds used toproduce a given plant response effect may be markedly reduced, or theplant response effect obtained with a given amount of active ingredientmarkedly increased, by admixing with any said compound or compounds, oneor more of the group consisting of the alkali metal (e. g. sodium andpotassium) and ammonium salts of peroxydisulfuric acid, commonly knownas persulfuric acid; said salts being either in neutral or acid form.

Examples of such salts are sodium persulfate, sodium acid persulfate,potassium persulfate, potassium acid persulfate, ammonium persulfate,ammonium acid persulfate, and ammonium potassium persulfate.

As pointed out above, the persulfates contemplated include both the acidpersulfates and the neutral persulfates, and mixed neutral persulfates,that is, persulfates in which the cations are different.

The preparation of persulfates may be accomplished by any means known tothe art, and. suitable methods will be found in the literature.

Likewise, the preparation of the 3,6-endoxohydro-orthophthalic acids,per se and in equiva- 4' lent form, may be accomplished by any meansknown to the art, and suitable methods will suggest themselves topersons skilled in chemical synthesis upon becoming familiar with thechemical structure of such compounds.

The amount of additive or intensifier to be admixed with the endoxocompounds may vary over a very wide range. A small amount will produce auseful synergistic intensifying effect. On the other hand, andparticularly since I have discovered that my intensifiers are inthemselves capable of inducing phytotoxic effects, I contemplate the usewithin the broad scope of my invention of proportions of intensifier farin ex cess of those proportions producing optimum synergisticintensifying action. Thus in a sense either the endoxo compound or thepersulfate compound may be regarded as the principal ingredient, and theother as the intensifier, since in any event a synergistic effect isproduced by their admixture.

Generally speaking, for practicable purposes, proportions of intensifierto active ingredient of from 1:50 to 50:1, and particularly from 1:10 to10:1 are very useful.

The intensifier and the active ingredient may be admixed in any desiredmanner such as by mere mechanical mixing in solid form, or while insolution in a common solvent such as water. It is of course preferredthat solid admixtures be in finely divided, free-flowing form.

The admixtures are applied to the crop or plants in any desired manner,such as in the form of a solid, for example, by dusting, or in the formof a liquid, for example, by spraying.

Compositions may be formulated by mixing the admixture containing theintensifier and active ingredient with any desired liquid or solidcarriers, such as any of the finely divided solid carriers known in thedusting art, which are preferably of large surface area, such as clay,for example, fullers earth, pyrophyllite, talc, bentonite, kieselguhr,diatomaceous earth, etc. Any of the commercial clays available on themarket in finely divided form may be used, and particularly those whichare normally employed as insecticide carriers. Commercial clays, it willbe understood, are generally identified by trade names (reflecting thesource and mode of processing), of which Homer Clay, Celite, and Tripolimay be mentioned as typical.

Non-clay carriers which may be formulated with my admixture include, forexample, sulfur, volcanic ash, calcium carbonate, lime, by-productlignin, lignocellulose, flour, such as wood, walnut shell, wheat,soybean, potato, cottonseed, etc.

Any desired mixture may be prepared by any suitable method. Thus, if asolid, the active ingredient may be ground to a fine powder and tumbledtogether with the intensifier, or the intensifier and the activeingredient may be ground together; alternatively, the active ingredientin liquid form, including solutions, dispersions, emulsions, andsuspensions thereof, may be admixed with the intensifier in finelydivided form in amounts small eough to preserve the freefiowing propertyof the final dust composition. Or excess liquid may be removed, such asby vaporization, for example, under reduced pressure. The same appliesto mixtures of the active ingredient, the intensifier, and any finelydivided solid carrier and/or other material.

When solid compositions are employed, in order to obtain a high degreeof plant coverage with minimum poundage per acre, it is desirable thatthe composition be in finely divided form. Preferably, the dustcontaining the active ingredient should be sufficiently fine thatsubstantially all will pass through a 50 mesh sieve, and

more particularly through a 200 mesh sieve. Excellent results have beenobtained in which the dust composition is comprised predominantly ofparticles in the range from to microns. Finer dusts, such as thoseconsisting largely of particles in the range of 5 microns and below haveexcellent covering capacity but are some- What more subject to drift andare more expensive to prepare.

For spray application the admixture may be dissolved or dispersed in aliquid carrier such as water or other suitable liquid.

Aqueous solutions or dispersions are economical and desirable. Ingeneral, the choice of the particular liquid carrier employed will beguided somewhat by prevailing circumstances, such as its availability,its solubility or dispersion characteristics toward the particularadmixture employed, and/or its toxicity toward the plants undergoingtreatment. In general, water is an excellent liquid carrier.

Thus, spray formulations comprising the active ingredient in the form ofa solution, suspension, dispersion, or emulsion, in aqueous ornon-aqueous media may be employed.

Emulsions or dispersions of the admixture in the liquid carrier may beprepared by agitation of the admixture with the carrier. This iscommonly done at the time of spraying. Preferably, however, theagitation should take place in the presence of an emulsifying ordispersing agent (surface-active agent), in order to facilitate thepreparation of said emulsion or dispersion. Emulsifying and dispersingagents are well known in the art, and include, for example, fattyalcohol sulfates, such as sodium lauryl sulfate, aliphatic or aromaticsulfonates, such as sulfonated castor oil or the various alkarylsulfonates (such as the sodium salt of monosulfonated nonyl naphthaleneor tertiary dodecyl benzene), and non-ionic types of emulsifying anddispersing agents such as the high molecular weight alkylpolyglycolethers or analogous thioethers such as the decyl, dodecyl andtetradecyl polyglycolethers and thioethers containing from 25 to 75carbon atoms.

The use, if desired, of adjuvants, such as wete ting agents and/orhumectants, is also contemplated in connection with solid formulationsand solutions of the admixture, such as water solutions. humectant maybe employed for this purpose, such as the wettin agents moreparticularly referred to above. Examples of humectants are glycerine,diethylene glycol, ethylene glycol, polyethylene glycols generally, andwell known sugar-containing mixtures, such as corn syrup and honey.

For adjuvant purposes, any desired quantity of wetting agent may beemployed, such as up to 250% or more based on active ingredient andintensifier. For wetting purposes, the amount of adjuvant used may beconsidered to be that required to impart the desired wettingqualities tothe formulation, whether used in finely divided solid form or as a spraysolution, or otherwise, such as from approximately 0.005% to 0.5% byweight of total formulation. The use of considerably larger amounts isnot based upon wetting properties, although present, but is a func- Anysuitable wetting agent and/or tion of the physiological behavior of thewetting agent after sprayin upon the plant.

It should be considered that once the formulation has been applied tothe plant, the concentration of wetting agent existing upon the plant isin no sense a function of the concentration existing in the originalformulation, particularly in the ease of a spray solution. Thus,evaporation might concentrate the wetting agent considerably in the caseof a spray solution, or the presence of dew on the plant surfaces, or ofplant juices on the plant surfaces might considerably dilute the wettingagent.

As will be seen, wetting agents, particularly when in solid form, may becompounded with the admixture when in solid form.

Although the admixture of active ingredient and intensifier may beapplied to the growing plant in concentrated form, it is usuallydesirable to employ liquid or solid formulations, for example, asdiscussed above, in which the active ingredient and intensifierconstitute less than 30% by weight of the total, such as less than 10%and even as low as 0.1%.

Other substances than the carrier and/or surface active agent may beincluded in solid or liquid formulations if desired. Thus, activeingredients and/or intensifier-s other than those disclosed herein andcompatible with the acl1nixture may be added if desired for anyparticular purpose. Also substances may be added to bring about variousphysical improvements such as the prevention of lumping during storage,or improvement with respect to coverage, moisture adsorption, adherence,etc. Such other active ingredients and/or intensifiers may be includedin said formulations to accomplish various physiological or othereffects. For example, it may at times be expedient to include singly orin combination, substances such as fungicides, insecticides,bactericides, fertilizers, or types of plant response agents other thanthose agents discussed herein.

In practice of the process as applied to de foliation, the rate ofapplication (i. e. the amount of admixture per crop unit) for bestresults will depend among other factors upon the species of plants beingtreated and upon their maturity. In any event, the amount of activeingredient employed for the same plant response effect will besubstantially lower than when the intensifier is not present.

.As a rule the more mature the plant at the time of application, theless active material is required. In practice, the crop is normallytreated for defoliation purposes, 1 or 2 weeks prior to harvesting. Insome instances, more than one application may be desirable, especiallyif heavy rains or winds should occur soon after the application, or toobtain an accumulative effect. Then too, in order to avoid possibleinjury to any particular crop, it may be desirable for an inexperiencedoperator to apply the formulation initially at a relatively low rate,and to follow with a second application if necessary after observationof the first effects, to obtain the degree of defoliation desired.

Use of dosages greatly in excess of the minimum required for gooddefoliation may result in shock to the plant with attendant injury tothe remainder of the plant.

In fact, the plant response compositions of the present invention areeffective herbicides when used in amounts substantially greater thanthose required for defoliation, and they may be used advantageously forthe killing of plants or vines (as in the case of potatoes) whendesired, such as, for the killing of undesired plants, for example,weeds or grasses, or for the killing of crops, irrespective of whethersuch undesired plants or crops are of species which lend themselves todefoliation.

Thus when defoliation is the objective the quantity applied should besuflicient to cause at least the major portion of the leaves to dry upand/or to drop from the living plant, but insufficient to causesubstantial herbicidal action on the plant. On the other hand, whenplant killing is the objective, any amount sufficient for this purposemay be applied. In the latter connection, since different species ofplants vary markedly in their relative resistance to herbicidal action,selective killing of plant species may be practiced. Such selectivitymay be varied by compounding, such as with adjuvants, for example,wetting agents, in addition to the use of an intensifier.

I am aware of the fact that it has been proposed to use certain ammoniumsalts, such as ammonium sulfate, in combination with phenolicsubstances, such as dinitroalkylphenols and pentachlorophenol, for plantresponse purposes. The purpose of such use of ammonium salts asexplained by Crafts and Reiber, Hilgardia, volume 16, pages 48'7499, andby Crafts, Science, volume 108, pages 85-86, is to make available thefree phenol at the plant surface from an aqueous solution of awater-soluble salt of said phenol. The phenol in such cases is theactive plant response substance and is continuously regenerated at theplant surface from its watersoluble salt by virtue of the presence ofthe ammonium salt. As the free phenol is absorbed by the plant surface,further free phenol is generated under equilibrium conditions. The plantresponse effect of the free phenol is not enhanced or intensified bysuch procedure, or in other words, is substantially the same as thatobtained by the application directly to the plant of a similar quantityof free phenol. In view of the insolubility of the phenol in water, thisprocedure is adopted in order to make available the use of water as avehicle for appl ingthe plant response agent, i. e. herbicide, to theplant surfaces.

In the case of my invention, on the other hand, the plant responseeffect obtained from a given quantity of active ingredient is greaterthan that obtained by the application of the same quantity of myintensifier. The intensification begins to manifest itself by theaddition of a small proportion of my intensifier and increases to apoint of optimum intensification by the addition of increasingproportions of intensifier. For optimum plant response effects, theproportion of intensifier to active ingredient may vary somewhat betweenspecific active ingredients and between specific varieties of plantsundergoing treatment, so that the exact proportion for optimum effectunder all conditions cannot be given. However, the intensification ofthe plant response effect is present when a small quantity ofintensifier is added, and the addition of intensifier beyond the pointat which no further marked increase in synergistic intensification isobtained does no harm, and may have a very useful purpose, for, and asbrought out above, generally speaking either the endoxo compounds or thepersulfate compounds may be regarded as the active ingredients with theother regarded as the synergistic intensifiers, since both exhibitmarked plant response effects, although for purposes of particulardescription, I prefer to regard the endoxo compounds as the activeingredients and the persulfate compounds as the synergisticintensifiers.

The exact mechanism by which the synergistic intensification of theactive ingredient is obtained in the practice of my invention is notknown. However, such synergistic intensification is cogentlydemonstrated by the following examples which are by way of illustrationand not of limitation.

Example 1 Separate groups of eight potted Dwarf Horticultural beanplants at the stage at which the first trifoliate leaf was still furledwere dipped to the first nodes into the respective test solutions used,and the excess solution was shaken off.

The test solutions were 0.062%, 0.125%, 0.25%, 0.5%, and 1.0% aqueoussolutions of ammonium persulfate, ammonium thiocyanate, ammoniumsulfamate, and ammonium sulfate, respectively.

Observations made six days after the applications were as follows.

In the following table, 48, for example, means each of four plants had asingle primary leaf abscised; 2B, for example, means each of two plantshad both primary leaves abscised. PL means primary leaves; TS meanstrifoliate shoots. The same code applies wherever apof the particularactive ingredient to the plant 55 plicable in the other examples.

Physiological elleets Concentration Ammonium persulfate Ammoniumthiocyanate Ammonium sulfamate Ammonium sulfate 0.062% PL partlyshrivelled; TS PL moderately burned; TS No effect No effect.

slightly retarded. not retarded. 0.125% 2B, 4S; adhering PL partly PLeonsiderablyburned; TS No ef ect No effect.

shrivelled; TS considerslighted retarded. ably retarded. 0.25% 2B, 48;adhering leaves 18; PL partly shrivelled;TS PLlight margmal urns;TSPLlight marginal burns; 'lS

withered and frozen; considerably retarded. slightly retarded.unaffected. TS considerably retarded. 0.5% 8B; TS severely retarded 58;PL shrivelled to with- PL considerably burned to PL moderate marginalandconsiderablyinjured. ered; TS severely repartly shrivelled; TSseburns;TSunaflected.

tarded. verely retarded. 1.0% One plant dead, four dying, 3B, 38; PLwithered and PL shrivelled; TS severely PL considerably burned to threeseverely injured. frgzeln; TS severely reretarded. shtrivflllgd; TSconsiderably tar e re ar e in the absence of my intensifier.

In fact, the

The term frozen as used to describe a conplant response effect obtainedwith the same quantity of active ingredient may be increased many timesby the addition of larger quantities dition of the leaves of a planttreated with a defoliant denotes that condition in which the leaves haveundergone such a quick and drastic Example 2 Two series of aqueoussolutions of disodium 3,6-endoxohexahydro-orthophthalate were prepared,one without and one with 0.05% of ammonium persulfate, at the followingconcentrations of the former: and 0.005%.

For testing purposes, the procedure of the preceding example wasfollowed with the same kind of bean plants.

Observations made four days later were as follows. The symbol A in thetable represents disodium 3,6-endoxohexahydro-orthophthalate.

In the interpretation of data as to defoliation, it must be kept in mindthat some leaves on individual plants are much more suspectible todefoliation than other leaves, and that, consequently, it is relativelymuch easier to bring about defoliation of say to 60%, than to carry thedefoliation up to say 75% to 95% or higher. It does not follow,therefore, that substantially complete defoliation can be caused merelyby the use of more, percentagewise, of the same defoliant. In otherwords, a high degree of defoliation is relatively speaking much moredifiicult to attain than moderate defoliation. Thus the data of thepreceding Example 3 definitely demonstrates the presence of markedsynergism.

Example 4 In this experiment, the test solutions were spray-misted ontoindividual groups of potted Henderson bush lima beans, using the sametechnique as in Example 3. Each group consisted of twelve plants at astage of growth at which the first trifoliate leaf was well developed.

The respective aqueous test solutions contained: (A) 0.5% of disodium3,6-endoxohexahy- Physiological effects Cone. of A Without (NH4)2S20BWith 0.05% (NH4)2S2OE 18; PL partly shrivelled; TS

5B, 28; PL considerably burned; TS considerably retarded.

2B, 2S; adhering PL withered and frozen; TS severely retarded.

0.005% 6B, 28; adhering PL withered 1B; adhering PL withered and andfrozen; TS severely frozen; TS severely reretarded. tarded.

Example 3 A 1.0% aqueous solution of disodium3,6-endoxohexahydrc-orthophthalate was spray-misted by means of a smallDe Vilbiss atomizer onto a group of twelve potted young DwarfHorticultural bean plants. The plants were at a stage of growth at whichthe first and second trifoliate leaves had developed.

This group of plants was arranged uniformly in a 2 foot by 3 foot area,and 3 ml. of test solution was uniformly sprayed in the described manneronto the area. This rate of application corresponds to 6 gallons peracre; this low volume rate simulates practical conditions of aeroplanesprayina. Thus the amount of disodium 3,6-endoxohexahydro-orthophthalate was 0.5 pound per acre. This test will besymbolized in the table below as A.

A parallel test was carried out in which the 1.0% aqueous solution ofdisodium 3,6-endoxohexanydro-orthophthalate also contained 5.0% ofammonium persulfate. Thus the amount of ammonium persulfate was 2.5pounds per acre.

Test Physiological efiects A defoliation; no stem or petiole injury. B98% defoliation; considerable stem or petiole injury. 0 defoliation; nostem or petiole injury.

dro-orthophthalate; (B) 0.5% of the same plus 2.5% of potassiumpersulfate; and, (C) 0.5% of the same plus 2.5% of ammonium persulfate.

The following physiological effects were observed after five days:

A. Approximately 15% defoliation B. Approximately 25% defoliation C.Approximately 75% defoliation Ezcample 5 Separate groups of eight pottedDwarf Horticultural bean plants at the stage at which the firsttrifoliate leaf was still furled were treated with aqueous testsolutions by the procedure of Example 1.

One group was treated with 0.1% ammonium persulfate and one day later itwas observed that the plants were considerably burned. Another group wastreated with 0.1% potassium persulfate, and after the same interval itwas observed that the plants were lightly to moderately burned.

In contrast, another group treated with 5% ammonium sulfate was notaffected after one day. Still another group was treated with 10%ammonium sulfate; after one day, some of plants were not affected andsome were only lightly burned.

The endoxo compounds are capable of exist ing in three separate anddistinct geometrically isomeric forms, namely, the exo-cis isomer, theendo-cis isomer, and the trans isomer, as defined by Woodward and Beer,Journal of the American Chemical Society, '70, 1161-4166. Of these threeisomers the exo-cis isomer is preferred in view of its generally greateractivity.

Furthermore, the 'exo-cis isomer can be prepared more economically andconveniently. The endoxo ingredient in the foregoing examples was of theexo-cis isomeric form.

When the endoxo ingredients are used in the form of the acids per seand/ or their anhydrides, aqueous solutions containing such acids and/oranhydrides probably contain non-ionized acid and/or anhydride inequilibrium with ionized material. Similar considerations might apply tosome of the salts.

The alkylammonium salts of 3,6-endoxohydroorthophthalic acids, such asmonoalkylammonium, dialkylammonium, or trialkylammonium salts preferablyhave from 1 to 12 carbon atoms in each alkyl radical, the totality ofcarbon atoms in such alkyl radical or radicals preferably being not morethan 12. The alkanolammonium salts such as monoalkanolammonium,dialkanolan monium, or trialkanolammonium preferably have from 2 to 3carbon atoms in each alkanol radical. The mixed alkylalkanolammoniumsalts such as monoalkyl monoalkanolammonium, dialkylmonoalkanolammonium, or monoalkyl dialkanolammonium preferably have from1 to 4 carbon atoms in each alkyl radical and from 2 to 3 carbon atomsin each alkanol radical.

The following are examples of salts of 3,6-endoxohydro-orthophthalicacids.

Examples of monoalkylammonium salts are the monomethylammonium,monoethylammonium, monopropylammonium, monobutylammonium,monoamylammonium, monohexylammonium, monoheptylammonium, monooctylammonium, monononylammonium, monodecylammonium, monium and similarmonoalkylammonium salts of such acids.

Examples of dialkylammonium salts are the dimethylammonium,diethylammonium, dipropylammonium, dibutylammonium, diamylammonium,dihexylammonium, methylethylammonium, ethylpropylammonium,propylbutylammonium, butylamylammonium, amylhexylammonium,methylundecylammonium, and similar dialkylammonium salts of such acids.

Examples of trialkylammonium salts are the trimethylammonium,triethylammonium, tripropylammonium, tributylammonium,methyldiethylammonium, ethyldipropylammonium, propyldibutylammonium,methyldiamylammonium, eth- 4 yldiamylammonium,methylethylpropylammonium, ethylpropylbutylammonium, and similar saltsof such acids.

Examples of monoalkanolammonium salts are the monoethanolamrnonium,monopropanolammonium, and similar salts of such acids.

Examples of dialkanolammonium salts are the diethanolammonium,dipropanolammonium, ethanolpropanolammonium and similar salts of suchacids.

Examples of trialkanolammonium salts are the triethanolammonium,tripropanolammonium, ethanoldipropanolammonium,propanoldiethanolammonium and similar salts of such acids.

Examples of monalkyl monoalkanolammonium salts are themethylethanolammonium, ethylethanolammonium, propylethanolammonium,butylethanolammonium, methylpropanolammonium, ethylpropanolammonium,propylpropanolammonium, butylpropanolammonium, and similar salts of suchacids.

Examples of dialkyl monoalkanolammonium salts are thedimethylethanolammonium, diethylethanolammonium,dipropylethanolammonium, dibutylethanolammonium,dimethylpropanolammonoundecylammonium, monododecylainmonium,diethylpropanolammonium, dipropylpropanolammonium,dibutylpropanolammonium, methylethylethanolammonium,methylethylpropanolammonium, ethylpropylethanolammonium,ethylpropylpropanolammonium, propylbutylethanolammonium,propylbutylpropanolammonium, and similar salts of such acids.

Examples of monoalkyl dialkanolammonium salts are themethyldiethanolammonium, ethyldiethanolammonium,propyldiethanolammonium, butyldiethanolammonium,methyldipropanolammonium, ethyldipropanolammonium,propyldipropanolammonium, butyldipropanolammonium,methylethanolpropanolammonium, ethylethanolpropanolammonium,propylethanolpropanolammonium, butylethanolpropanolammonium, and similarsalts of such acids.

As pointed out above the salts contemplated include both the acid saltsand the neutral salts, and mixed neutral salts, that is salts in whichthe cations are different.

The term plant as used herein is understood to include all portions ofthe plant, such as the roots, stems, leaves, blossoms, seeds, andfruits.

Among the plants which defoliate naturally and which may be defoliatedby the use of this invention, are for example, cotton, potatoes,tomatoes, and beans such as soy beans and lima beans.

Among the noxious weeds against which my compositions evidenceoutstanding herbicidal properties are the following: bindweed,chickweed, cocklebur, mares tail, shepherds-purse, broad-leavedplantain, wild lettuce, ragweed, spurge, dock, and wild carrot.

My new compositions are generally applicable as herbicides, such as inpre-emergence or preplanting practices for the control of weeds, inpost-emergence treatment for control of weeds as to such useful crops towhich the formulation evidences only slight or no herbicidal action, andotherwise following agricultural practices.

From the foregoing it can be seen that the endoxo compounds used in thepractice of this invention, whether used as the acid or in some otherform, are highly effective in regulating the growth characteristics ofviable or living plants, and particularly of plants having vascularsystems, when used in admixture with the persulfates of this invention.For example, the admixture may be employed to hasten defoliation ofplants which defoliate naturally, or may be employed to terminate thelife cycle of plants, or may be employed to retard the growing of seeds,or may be employed to selectively stunt or terminate the growth ofcertain unwanted plants to facilitate and favor the growth of wantedplants, or may be employed to terminate the growth of vines in favor of,or to facilitate harvesting of, the fruits of such vines, or may beemployed to stimulate root growth on cuttings, etc. Other applicationsof the invention in the regulation of the growth characteristics ofplants will occur to persons skilled in the art upon becoming familiarherewith.

Accordingly, it is to be understood that the particular description isby way of illustration and that the patent is intended to cover bysuitable expression in the claims whatever features of novelty reside inthe invention.

This application is a continuation-in-part of my copending applicationSerial No. 161,255, filed May 10, 1950, now Patent 2,576,083 grantedNovember 20, 1951.

I claim:

1. A plant response composition comprising a compound which when in thepresence of water yields anions of an acid of the group consisting of3,6-endoxo-1,2,3,6-tetrahydro-orthophthalic acid and 3,6 endoxohexahydroorthophthalic acid, and a salt of persulfuric acid with at least one ofthe group consisting of sodium, potassium, and ammonia.

2. A plant response composition comprising a compound which when in thepresence of water yields anions of 3,6-endoxohexahydro-orthophthalicacid, and a salt of persulfuric acid with at least one of the groupconsisting of sodium, potassium, and ammonia.

3. The composition of claim 2 in which said anion is in the exo-cisisomeric form.

4. The composition of claim 3 in which said salt is an ammoniumpersulfate.

5. The composition of claim 4 in which said salt has the composition(NH4)2S2Oa.

6. The composition of claim 5 having admixed therewith a wetting agent.

7. A plant response composition comprising a compound which when in thepresence of water yields anions of3,6-endoxo-1,2,3,6-tetrahydroorthophthalic acid, and a salt ofpersulfuric acid with at least one of the group consisting of sodium,potassium, and ammonia.

8. The composition of claim 7 in which said anion is in the exo-cisisomeric form.

9. The composition of claim 8 in which said salt is an ammoniumpersulfate.

10. The composition of claim 9 in which said salt has the composition(NH4)2S208.

11. The composition of claim 10 having admixed therewith a wettingagent.

12. A method of regulating the growth characteristics of a plant, whichcomprises applying to said plant in amount sufficient to obtain thedesired effect a composition comprising a compound which when in thepresence of water yields anions of an acid of the group consisting of3,6-endoxo-1,2,3,6-tetrahydro-orthophthalic acid and 3,6 endoxohexahydroorthophthalic acid, and a salt of persulfuric acid with at least one ofthe group consisting of sodium, potassium, and ammonia.

13. A method for inducing plant response in a living plant, comprisingapplying to said plant in amount suflicient to obtain the desired effecta composition comprising a compound which when in the presence of wateryields anions of exo-cis-3,6-encloxohexahydro-orthophthalic acid, and asalt of persulfuric acid with at least one of the group consisting ofsodium, potassium, and ammonia.

14. A method for inducing plant response in a living plant, comprisingapplying to said plant in amount sufficient to obtain the desired effecta composition comprising a compound which when in the presence of wateryields anions of exo-cis- 3,6-endoxo-1,2,3,6-tetrahydro-orthophthalicacid, and a salt of persulfuric acid with at least one of the groupconsisting of sodium, potassium, and ammonia.

15. A method of regulating the growth characteristics of a plant whichcomprises applying to said plant in amount sufficient to obtain thedesired eifect a salt selected from the group consisting of the sodium,potassium, and ammonium salts of persulfuric acid, said salt havingadmixed therewith disodium exo-cis-3,6-endoxohexahydro-orthophthalate.

16. A method of regulating the growth characteristics of a plant whichcomprises applying to said plant in amount sufficient to obtain thedesired effect an ammonium salt of persulfuric acid, said salt havingadmixed therewith disodium exocis-3,6-endoxohexahydro-orthcphthalate.

17. The method of claim 16 in which the salt has the composition(NI-1028208.

18. The method for inducing a phytotoxic response in a living planthaving a vascular system, comprising bringing into association with saidvascular system of said plant an effective amount of a. compositioncomprising a salt selected from the group consisting of the sodium,potassium, and ammonium salts of persulfuric acid, and a compound whichwhen in the presence of water yields anions ofeXo-cis-3,6-endoxohexahydroorthophthalic acid.

References Cited in the file of this patent FOREIGN PATENTS NumberCountry Date 16,014 Great Britain July 6, 1395 of 1894 OTHER REFERENCESNew Zealand J. of Agriculture, March 20, 1934, pages 172 and 173.

Thorpe, Dictionary of Applied Chemistry (1921), vol. 7, page 455.

1. A PLANT RESPONSE COMPOSITION COMPRISING A COMPOUND WHICH WHEN IN THEPRESENCE OF WATER YIELDS ANIONS OF AN ACID OF THE GROUP CONSISTING OF3.6-ENDOXO-1,2,3,6-TETRAHYDRO-ORTHOPHTHALIC ACID AND 3,6 -ENDOXOHEXAHYDRO - ORTHOPHTHALIC ACID, AND A SALT OF PERSULFURIC ACIDWITH AT LEAST ONE OF THE GROUP CONSISTING OF SODIUM, POTASSIUM, ANDAMMONIA.